Electronic circuit control and relay therefor



Dec- 7, 1948 H. H. wElcHARDT 2,455,395

ELECTRONIC CIRCUIT CONTROL AND RELAY THEREFOR 2 Sheets-Sheet 1 Filed Dec. 8, 1943 ma @mmf Syd/ul* VM/da ATTORNEY: Y

Dec. 7,1948. H, wElCHARQ- r v 2,455,395

ELECTRONIC CIRCUIT CONTROL AND 'RELAY THEREFOR Filed Dec. 8, 1945 2 Sheets-Sheet 2 Ef Ep [VJ mmw INVENTOR BY ff//vZ//WA//NM/CHA/r www QV.. 5%.1 L www ATTORNEY.:

Patented Dec. 7, 1948 ELECTRONIC CIRCUIT CONTROL AND RELAY THEREFOR Heinz Hermann Weichardt, New York, N. Y., as-

signor to Tung-Sol Lamp Works, Inc., Newark,

. E., a corporation of Delaware Application December 8, 1943, Serial No. 513,453

15 Claims.

This invention relates to relays and controls for electronic circuits, and particularly circuits embodying elctronic devices having elements energized by batteries.

In designing tubes for battery operated radio receivers, sets and the like, the difficulty arises to produce tubes which will remain within specified electrical limits in spite of changing filament supply voltage. For example, a fresh battery will usually give up to 1.6 volts but as it is used will drop down to nearly 1 volt before it is entirely exhausted and it is diflicult to design tubes which will efficiently operate with this large variation in voltage supply of from 1.6 volts down to l volt.

One object of the invention is a radio circuit and a control therefor which will enable this differential in starting and ending voltage to be substantially reduced, as for example, by half or more. In carrying out this object of the invention the unduly large range in voltage differential can be reduced by approximately half by designing the tubes to operate at a smaller filament voltage than is customarily used, for example, at 1.2 volts instead of 1.4 volts, and by connecting in circuit with the filaments a series resistor such as will drop the voltage of a fresh battery down to approximately the required efficient operating voltage. As soon as the battery is partially exhausted or sufficiently exhausted to reduce the voltage below the value required for eicient operation of the tubes with the resistor in series, the latter is then removed from the circuit as by short-circuiting and the tube filament or filaments can now be operated directly from the battery until the battery is exhausted. Efficient and satisfactory operation of the circuit is thereby obtained notwithstanding the large variation between the voltage of the fresh battery and. the voltage of the exhausted battery.

A further object of the invention is a novel and improved control for effecting the removal or short-circuiting of the resistor in series with the battery supplying the filaments of the tubes.

A further object of the invention is such a con-- trol circuit which is characterized by the sim.- plicity with which it may be manipulated by the user of the circuit to remove the resistor connected in series with the `partially exhausted battery.

A further object of the invention is such a control embodying a novel and improved relay circuit for controlling the resistor.

A further object of the invention is a novel and improved relay which is characterized by a sensitivity out of proportion to the comparatively small changes in battery voltage.

A further object of the invention is a relay and relay circuit characterized by connection of the relay coil in the plate circuit of an electronic tube with the filament of the tube connected across the varying supply voltage whereby changes in supply voltage are multiplied in the plate circuit.

Further objects of the invention will hereinafter appear.

For a better understanding oi the invention reference may be had to the accompanying drawings forming a part of this application, wherein:

Fig. 1 is a circuit, schematically illustrated, embodying the invention;

Fig. 2 to 6 inclusive are diagramatic views of a manually controlled relay circuit embodying the invention;

Fig. 7 is a graph of the Ip--Ef curve of the diode or radio tube element of the relay combination; and

Fig. 8 is a graph showing the reduction of battery voltage change through the action of the control embodying the invention.

The invention is illustrated as applied to and embodied in an electronic circuit, such as a radio receiver set comprising tubes l, two of which are shown. The heating filaments for the tubes are indicated at 2 and these filaments are energized by the conventional battery A resistor 4. is connected in series with the filament supply circuit and the set is designed to give efiicient operation with the resistor 4 in circuit when the battery 3 is fresh or nearly fresh and is therefore capable of giving its maximum or approximately maximum voltage. So long as the battery 3 is not discharged or exhausted to a point where the voltage drops below a predetermined value the resistor 4 is maintained in circuit but when the exhaustion of the battery is sufcient to bring the voltage down to a .predetermined value the resistor 4 is or may be removed from the circuit as by short-circuiting the same.

The means for removing the resistor t from the circuit comprises a relay coil 5, relay contacts t (Fig. l) controlled by the coil, an electronic tube such as a diode 1, a battery S and a manually controlled switch 9. This battery B may be the B battery of the set, in which case no additional battery is needed. are connected by means of the wires ID across the terminals of the resistor l so that when these contacts are closed the resistor l is short-circuited and the full voltage given by the battery 3 is applied to the heating filaments 2. One side The relay control contacts 6 locking part 29 of the lever 25. When the user suspects that the battery 3 is no longer sulcient to energize the filaments 2 of the tube for efficient and satisfactory operation of the set, he merely pushes the push rod 4D inwardly toward the lever 25, namely to the right as shown in the figures. This movement first releases the relay armature by the pin 41 engaging the lefthand end 30 of the lever and turning the lever about the pivot 26. This permits the armature 5 of the unenergized relay coil 5 to drop counterclockwise about the pivotal axis 20, the spring arm 22 assisting in this counterclockwise movement of the armature by engaging the actuating finger 23. A continued movement of the push rod 40 results in the engagement of the upturned end 35 of the spring iinger 35 and the closure of the contacts 9. The closure of the switch 9 energizes the iilament I6 of the diode and if the voltage of the battery 3 is at or above a predetermined value a suiciently strong plate current will iiow through the relay coil 5 to cause the latter to actuate the armature 5 to the vertical position against the tension of the spring finger 22 and thereby reopen the contacts 6 which were temporarily closed when the lever 25 was iirst actuated. If the battery voltage of the battery 3 has decreased below the predetermined value, as, for example, to 1.3 volts, the plate current of the diode will not be suiicient for the relay coil 5 to actuate the armature 5 and accordingly the latter will remain in this position with the contacts 6 closed so as to short-circuit the resistor 4.

`The movement of the push rod 40 to the right results in the pin 41 riding over the leaf spring 33 but as soon as the pin 41 rides over the free end of the spring 33 the spring 21 actuates the lever 25 to bring the latter into engagement with the pin 41 again. During the backward movement of the push rod 40 the pin 41 rides under the spring 33 and when it reaches the slot 32 is caused by the swinging of lever 25 under the tension of spring 21 to pass through the slot so that the further backward movement then results in the pin 41 engaging the under surface of the lever 25. Figs. 4 and 5 indicate the positions where the pin 41 is at the end of its righthand stroke, and has just passed through the slot 32, respectively. Fig. 6 shows the position where the push rod 40 is nearings its lefthand position and just before the pin 41 has passed out from under the end 30 of the lever 25.

The switch 9 which is thus closed when the push rod 40 is moved to the right is maintained closed until after the lever 25 is moved by the spring 21 to the horizontal position so as to assure the locking of the armature 5 in the position to lock the contacts 6 open, if the voltage of battery 3 is above the predetermined value.

The desired sequence of the locking cr releasing of the armature 5' and of closing and opening the switch 9 may be eiIected in any suitable manner. In the particular embodiment shown, the pin 41 on its way to the right, depresses the lever 25, 30 and then the push rod 40 strikes the spring linger 35 of the switch 9 to close the same. The latter remains closed until the push rod returns to its original position.

The partially manual operation is desired to avoid any continuous use of power or the continuous energization of the diode and the battery 8 and to render the device sensitive when operated but positively locked or deenergized when not in operation, the lament of the diode being only energized when the push rod 40 is operated. The

only manual operation is the actuation of the push button or rod 40. The relay and cooperating mechanism function responsively to the relatively small change in voltage of the battery 3 to reopen the contacts 6 if the voltage of the battery is above the predetermined value or to permit the maintenance of the closure of the short-circuit il the voltage is below that predetermined value and this differentiating and distinguishing control are automatically effected responsive to the manual manipulation of the push rod 49. Further, the closing point of the relay is not appreciably changed by change of plate Voltage of the diode as, for example, with a diode plate voltage varying from 40 to 105 volts. For example, in the embodiment exemplified by the graphs, the closi ing point or battery voltage above which the relay is effective to operate the armature 5 does not vary from the 1.31 volts with a variation in plate voltage of from 40 to 70 volts, and varies very little up to a plate voltage of 105, namely to 1.29. In this particular embodiment the short-circuiting point for the resistor R was a voltage of 1.3.1. at a plate voltage of 45 volts (graph, Fig. '1). A voltage change from 1.1 to 1.5 volts in the battery is reduced by the relay and control set forth to a change from 1.1 to 1.31 volts of filament voltage. The regulation acts on changes of voltage and is independent of the number of tubes used in a particular set. Only the size of the resistor 4 has tu be adjusted to the total filament current of the set.

In the particular embodiment shown, the current supply to the filaments 2 is regulated by a battery supply and a controllable resistance in series but it is understood that certain features of the invention are applicable to other types of controls.

I claim:

l, Means for testing a battery in circuit with one or more vacuum tube iilaments and modifying said circuit in accordance therewith, comprising, a resistor in circuit with said battery when the battery is at full voltage, and relay control means responsive to the voltage of said battery for shortcircuiting said resistor when the voltage of the battery drops to a predetermined lower value through the use thereof in heating the aforementioned filaments.

2. In a control means for a resistance connected in series with a battery supplying energy to the heating lament of an electronic tube, the com bination of electromagnetic means controlling said resistance and responsive to the battery voltage when energized to maintain the resistance in circuit during the rst part of the life of the bat tery and until the battery voltage drops through discharge to a predetermined value and to cut out said resistance when the battery voltage drops through discharge to said predetermined value, with means momentarily energizing said electron magnetic means including a manually operated device for testing the voltage of the battery during the life of the latter.

3. In a battery operated vacuum tube filament circuit, means for testing the battery and causing the circuit to be modified if the battery voltage has fallen to a predetermined level, comprising a resistor in circuit with said battery, and relay control means responsive to the voltage oi said battery for short-circuiting said resistor when the Voltage of the battery drops to a predetermined value. said relay control means comprising a switch for short-circuiting said resistor, a relay coil and armature for controlling said switch, a

diode tube whoselenergiaing nlament'isfadaptedfto be connected across the battery, a source of direct currentsupply connected across the diode lament andthe-piateof the diode and the relay coil being connected betweenthe plate and the battery.

In a battery o'peratedvacuum tube Filament circuit, means for testing the battery and causing the circuit to be modified if the battery voltage fallen to predetermined level, comprising a resistor in circuit with said battery, and relay control means responsive to the voltage of said battery for ycontr fil' ig said resistor when the voltage of the battery :drops to a predetermined value. said relay Acontrol means comprising a switch .for sl rrt--circuiting said resistor, a relay coil and armature for controlling said switch, a diede tube whose energizing iilarnent is adapted to connected across the battery, a source of direct current supply `connected across the diode filament-and the plate of the diode'and therelay co-il being connected between the plate and the battery, andinanual means for connecting and disconnecting he larnent of the diode across said battery.

5. In an "electronic circuit,-ene or more tubes havingheating iiiaments'therein, a battery source of supply for energizing said filaments, a resistor circuit with said battery, and relay control means responsive tothe voltage of said battery for controilingsaid resistor when the voltage of the battery drops to a predetermined value, said relay control means comprising a switch-biased to closing position 'for short-circuitingsaid resistor, a relay coil for actuating said switch. against the bias thereof vto open the same, ain-electronic tube having one element adaptedto befenergized by the battery and its plate connected in circuit with a relay coil to cause the plate current yto flow through the coil7 and .means for controlling the circuitof said element 6. A. battery 'operated vacuum'tube heater circuit adapted to be modiiied when the batteryvoltage falls to a predetermined value to substantially restore thetubes to normal operating eilia -resistor'connected in circuit between the battery and the heaters and control means for saidr stor comprising a relay'coil responsive to the volage of said battery together with diode vacuum tube for amplifying the effect of voltage changes of the battery upon the relay for short-cir 'ting said resistor ir the voltageof the battery is below a predetermined valueand manually operable means for periodically energizing therelay coil.

7. In electronic circuit having one or more radio tubes having heating laments'therein and a battery supply for energizing said larnents, vrelay means for controllingthe voltage supplied by said battery to the filaments comprising a resistor'in thefbattery'circuitpa relay coil and an electronic tube having a iiiament adapted to be energiaedby said battery and its plate connected in series with the relay coil, and manual means controlling the circuit of the last said filament.

8. In a vacuum tube circuit having one or more vacuum tubes and a battery source of supply for energizing the larnents of said tubes, means for .modifying the voltage supplied by said battery to be filaments comprising a resistor in the battery circuit, a relay coil, an armature biased in a di rection oppositeto the pull of the coil, means for lockingsaid armature in-oneposition against the bias, a `n'ianual device for releasing said .locking 8 means :and :at vthe same time :energizing 1 the relay responsivelyto the battery voltage.

'9. lnA a vacuum vtube circuit .'havingzone ormore vacuum -tubes and a battery'sourcetof supply Ifor energizing the filaments of said'tube's, meansfor modifying the voltage supplied by'said battery to the filaments comprising a resistor in the'battery circuit, a relay coil, an armature, control contacts biased to closed position and biasing "said armature against the pullof the relay'coil, a pivoted lever having 'means on one end `for locking thearmature-in positiontolholdithe contactsopen and azreciprocable member havinga pin engaging one surfacefof one endof said lever to :release'the lock in one direction of movement and energizing the coil and iniits opposite direction ofmovement said pin disengaging said surface thereof to permit `the lever to resume its locking position.

l0. AIn a vacuum tube'circuit having one or more vacuum tubes and a battery'source of Asupply for energizing vthe laments of ysaid tubes,1'means.for modifying the voltage supplied by saidbattery `to thel'aments'comprising a resistor in the battery circuit, a relay coil, an armature, control vcontacts biased to yclosed :position -and biasing vsaid armature against 'the pull of the relay'coil, a pivoted leverhaving meanson one 'endffor locking the armature inpositiontohold the contacts open and a reciprocablemember having a, pin'engaging one surfaceof-onefendof said lever to release the lock in one directionof movement andenergizing the .coil and in its oppositeA direction'of/movement said pin passing through a slot insaid ylever to permit Ithe lever vto Aresume its :locking position, said reciprocable member 'having a pivoted end which carries 'said ypin land said lever having 'a guardmember giorforcing'the. pin through 'the slot in'- one direction of movement.

.1.1. lIn an-electroniccircuit, having electronic tubes and abattery for-energizing fthefilaments of'said tubes, a resistor betweenthe battery and the'ilamentsand means'for short-circuiting said resistor when the voltage ofthe battery drops to a predetermined value, comprising `an electromagnet'responsivetothevoltage of thebattery, a

switch yfor .short-circuiting said.-resistor, anarmature operated byisaidelectromagnet to'hold said switch open,vmeans for locking theiarmature in a position to hold said switch open, a Lcircuit for energizing said electromagn'eaanda manual device for'releasing saidv armature 'to permit Closure of said switch and said last named circuit.

12. The combination lof a battery voperated radio set with a .userbattery voltage testing and resistor cut-out deviceto modifythe heater circuit if the :filament battery voltageis below a .predetermined level,=comprising aresistorin theheater circuit, switch means rior short-circuitingthe resistor, a solenoidresponsive to the voltage of the battery for closing saidvswitchmeans Awhen'the battery Voltage drops to va predetermined value, means Afor locking said switch means in vopen position, a circuit-for energizing said solenoidinn cluding a battery and a tube havinga heated cathode responsive to the battery 4voltage and 'an anode plate and almanualdevice for releasing the locking means to permit closing of .the switch means if the voltage of the batteryisftoo low and for connecting the heated cathode'across the bat tery of the radio set.

13, In va control land testing means for the battery voltage supplied toa heating .lament of a radio tube, the combination of a switchmean's forshort-'circuiting aresistancein thehea'ter'icircuit when the voltage .of the `battery drops to fa predetermined Value, said switch means being biased to resistance short-circuiting position, an electromagnet having an armature tending to hold said switch means open when the magnet is energized but responsive to a predetermined drop in voltage of the battery to release the switch means and tc permit the closure thereof, means for locking said switch means in open position, a circuit for energizing said electromagnet including a source of direct current and a tube having a heated cathode and an anode plate, said cathode being heated by said battery, and manually operated means which upon movement in one direction first releases the switch locking means and then connects the heated cathode across said battery and when moved in the opposite direction rst releases said locking means and then opens the circuit of the electromagnet.

14. A circuit for detecting changes in voltage of a battery used to energize battery type vacuum tubes comprising a. diode vacuum tube, a circuit connectingr the lament of the diode across the terminals of the battery to be tested, a plate circuit for the diode including a plate battery and means in the plate circuit responsive to changes in current therein to indicate a change in the lament battery voltage.

15. Means under manual control for testing the battery of a battery operated circuit while under load and modifying said circuit if the battery voltage is below a predetermined level when the man. ual control is operated, comprising a resistor in said circuit, a, relay having contacts connected with said resistor, and manual means for placing said relay in condition to respond to the battery voltage, whereupon said contacts will close if the battery voltage is below a predetermined value. HEINZ HERMANN WEICHARDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 402,349 Pfatischer Apr. 30, 1889 1,473,417 Beetem Nov. 6, 1923 1,649,016 Buckley Nov, 15, 1927 1,687,474 Engle Oct. 9, 1928 1,789,730 Demasters Jan. 20, 1931 1,806,796 Gates May 26, 1931 1,899,000 Johnson Feb. 28, 1933 2,104,861 Gannett Jan. 11, 1938 2,262,845 Hartley Nov. 18, 1941 FOREIGN PATENTS Number Country Date 160,070 Germany July 25, 1903 

